Here are a few items to look for in xp zones as you level up, just for fun. As a cleric you really don't need to worry too much about your equipment. Being selective with your spell use to minimise mana expenditure and aggro gained while maximising ticks spent medding will give a far bigger boost than + mana (which only lets you med longer before being full mana, and thereafter have a larger reserve of mana in case the shin hits the fat).
Don't worry if you miss too many. YourCrushbone:
http://wiki.project1999.com/Prayer_Cloth_of_Tunare
Kurn's Tower:
http://wiki.project1999.com/Iksar_Berserker_Club
http://wiki.project1999.com/Burynai_Hide_Armor (select pieces)
Lake of Ill Omen/Warslik's Wods
http://wiki.project1999.com/Idol_of_Woven_Grass
Unrest
http://wiki.project1999.com/Bloodstained_Tunic
http://wiki.project1999.com/Ivory_Bracelet
http://wiki.project1999.com/Opalline_Earring
http://wiki.project1999.com/Savant%27s_Cap
Mistmoore
http://wiki.project1999.com/Bloodstone_Eyepatch
Karnor's Castle
http://wiki.project1999.com/Jarsath_Scale_Armor
http://wiki.project1999.com/Bone_Amu..._Blade_Turning
http://wiki.project1999.com/Book_of_Obulus
http://wiki.project1999.com/Donal%27...ts_of_Mourning
http://wiki.project1999.com/Kunzar_Cloak
http://wiki.project1999.com/Springwood_Club
Again, don't worry if you end up filling you slots with cloth/rawhide/chain/bronze (My cleric wore mesh from guk until around level 40). The most important thing is to heal and med. If you're a super cleric you may even interrupt some spells with stuns or root mezzed mobs to help the enc keep control. Just make sure you aren't at the top of the aggro list as you are meant to be healing, not taking damage!
Complete heal is incredibly powerful. If you are able to avoid aggro, you can start grouping in Karnor's Castle really early. My stable group's cleric started there at 41! Lots of items that drop there are worth 10s or even 100s of pp to vendors. Some are worth even more to players.
Sorry if these thoughts are a little incoherent, but I've been back and forth from the keyboard.